1. Field of the Invention
The present invention relates to a connection structure or a fastening structure wherein, for example, in the case of connection by a connector or fastening by a clip, completion of the fastening or the connection can be confirmed.
2. Description of the Related Art
For example, incomplete fastening of a clip used for fixing a component of an automobile or incomplete connection of a connector used for connecting piping of fuel or coolant may cause a serious accident or a serious defect, depending on the section to which connection or fastening is applied. Accordingly, means for confirming fastening of the fasteners or connection of connectors has been desired, along with connection tools of good workability.
For this reason, JP-A-2003-90314 discloses a clip which can be fitted in one operation, and detect any incomplete fitting in advance. When an engagement section is in contact with the outside diameter of a large-diameter section when a clip is fitted to a shaft member, a predetermined gap is formed between a fitting claw and an engagement projection.
Also, JP-A-8-210576 discloses a connector for a small-diameter pipeline wherein when a pipe is inserted to complete connection, a confirmation member is caused to slip off or fall off so that completion of the connection can be confirmed.
Meanwhile, an anti-theft device, including that disclosed in JP-A-8-185584, is known. The device intends to prevent theft by attaching a seal, a so-called LC resonance tag in which a resonance circuit including a coil and a capacitor is formed on an item of merchandise, and oscillating radio waves of a predetermined frequency from a transmitter. When the LC resonance tag is caused to resonate by the radio waves, the resonance radio waves (echo waves) are received by a receiver, thereby ascertaining the item. In the case where a thief attempts to take the article away, the anti-theft device outputs an alarm signal so as to prevent theft.
Japanese Patent No. 2,853,965 discloses a tableware identifying apparatus including: tableware on which LC resonance tags are attached, the resonance frequencies of the tableware LC resonance tags varying from one kind of tableware to another; a transmitter which sweeps by changing a transmitting frequency continuously or stepwise, and a receiver which receives radio waves transmitted from the transmitter; a memory which stores respective ID data of a plurality of kinds of LC resonance tags; and a data processor, which uses information included in the ID data of the detected LC resonance tag to display and register information. The tableware identifying apparatus specifies the kind of the LC resonance tag on the basis of reflected waves included in the received wave forms and thereby identifies the kind of the tableware.
Further, JP-A-2001-291080 discloses a technology of making a resonating function effective or ineffective by opening and closing a switch provided in parallel with a capacitor in a circuit providing the resonating function by connecting the capacitor and a coil in series with each other.
Conventionally, confirmation of fastening or connection of a clip, a pipe connector, or the like has relied on visual observation, a clicking sound at connection, or a manual check. Therefore, a fastening or connection site hidden in a shadow, or covered by a cover or the like, may fail to be observed by an operator. Even in a case where there is provided connection confirmation means for confirming connection as shown in the Patent Documents 1 and 2, it cannot be said that there is no possibility of an operator overlooking connection or fastening because of carelessness of the operator. Furthermore, because all the conventional methods require confirmation of connections by visual check, in the case where a number of fastenings or connections are included, the confirmation has been quite demanding work.
Meanwhile, as shown in Patent Documents 3 and 4, a detection apparatus utilizing an LC resonance tag has been proposed; however, utilizing such an LC resonance tag for fasteners or connecting tools has not yet been attempted.